From: Steve French <smfrench@gmail.com>
To: CIFS <linux-cifs@vger.kernel.org>
Cc: Joshua Rogers <linux@joshua.hu>
Subject: [PATCH] smb: client: validate change notify buffer before copy
Date: Thu, 6 Nov 2025 21:23:43 -0600 [thread overview]
Message-ID: <CAH2r5mtLBAwfk7YbgRkCnA4S7uNyiTGs7kDssa697pci=rCYDw@mail.gmail.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 327 bytes --]
SMB2_change_notify called smb2_validate_iov() but ignored the return
code, then kmemdup()ed using server provided OutputBufferOffset/Length.
Check the return of smb2_validate_iov() and bail out on error.
See attached (lightly updated to fix checkpatch warnings from Joshua's
original patch)
--
Thanks,
Steve
[-- Attachment #2: 0001-smb-client-validate-change-notify-buffer-before-copy.patch --]
[-- Type: text/x-patch, Size: 1523 bytes --]
From 37b8dd736e77d5936f9acf5b52359a496c4d01fe Mon Sep 17 00:00:00 2001
From: Joshua Rogers <linux@joshua.hu>
Date: Fri, 7 Nov 2025 00:09:37 +0800
Subject: [PATCH] smb: client: validate change notify buffer before copy
SMB2_change_notify called smb2_validate_iov() but ignored the return
code, then kmemdup()ed using server provided OutputBufferOffset/Length.
Check the return of smb2_validate_iov() and bail out on error.
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Cc: stable@vger.kernel.org
Fixes: e3e9463414f61 ("smb3: improve SMB3 change notification support")
Signed-off-by: Steve French <stfrench@microsoft.com>
---
fs/smb/client/smb2pdu.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index b0739a2661bf..8b4a4573e9c3 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -4054,9 +4054,12 @@ SMB2_change_notify(const unsigned int xid, struct cifs_tcon *tcon,
smb_rsp = (struct smb2_change_notify_rsp *)rsp_iov.iov_base;
- smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset),
- le32_to_cpu(smb_rsp->OutputBufferLength), &rsp_iov,
+ rc = smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset),
+ le32_to_cpu(smb_rsp->OutputBufferLength),
+ &rsp_iov,
sizeof(struct file_notify_information));
+ if (rc)
+ goto cnotify_exit;
*out_data = kmemdup((char *)smb_rsp + le16_to_cpu(smb_rsp->OutputBufferOffset),
le32_to_cpu(smb_rsp->OutputBufferLength), GFP_KERNEL);
--
2.51.0
next reply other threads:[~2025-11-07 3:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-07 3:23 Steve French [this message]
2025-11-07 15:22 ` [PATCH] smb: client: validate change notify buffer before copy Joshua Rogers
2025-11-07 16:23 ` Steve French
2025-11-08 4:37 ` Shyam Prasad N
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